Please help! Leaking thread on shower valve

I have a kohler stacked thermostatic valve that was all roughed in and leak free and was about to start tiling over, but like an idiot, I decided I needed some shut off valves.

Nothing was leaking before this.

But, one thing lead to another and I basically ended up reinstalling the valve to get the shutoffs in.

Now, all is back and the two supplies seem fine, no visible leak under pressure.

However, on the outlet side to the shower head (when capped and under pressure), there is small leak thru the threads.

I have a threaded in male adapter and I used tfe paste on the threads. The one that I removed (that didn't leak) was in pretty tight and tried to get this one in as tight...I fear it was overtightened.

What are my options now? Could the valve body have been damaged? The threads look ok and aren't striped.

Anything is possible and we do not have enough information to tell you what happened. I am also somewhat puzzled about what kind of revision you made. Are the shutoff valves on the supply lines to the valve or on the riser to the shower head(s)? Neither one should have required reinstalling the shower valve.

Cut your copper riser to the length to your shower head height,then
solder on your male adapter to your riser,do this before you put the riser on the faucet,after it cools apply thread sealant to male adapter and tighten into
faucet,now once you get it tight,now you can solder on your lug ell in its
proper position.